Communications networks offer increasingly sophisticated capabilities associated with the motion and/or position location sensing of a mobile device. New software applications, such as, for example, those related to personal productivity, collaborative communications, social networking, and/or data acquisition, may utilize motion and/or position sensors to provide new features and services to consumers. Moreover, some regulatory requirements of various jurisdictions may require a network operator to report the location of a mobile device when the mobile device places a call to an emergency service, such as a “911” call in the United States.
Such motion and/or position determination capabilities have conventionally been provided using Satellite Positioning Systems (SPS). SPS wireless technologies which may include, for example, the Global Positioning System (GPS) and/or a Global Navigation Satellite System (GNSS). A mobile device supporting SPS may obtain positioning signals as wireless transmissions received from one or more satellites equipped with transmitting devices. The positioning signal may be used by the mobile device to estimate geographic position and heading. Some mobile devices may additionally or alternatively obtain positioning signals as wireless transmissions received from terrestrial based transmitters to estimate geographic position and heading and/or include one or more inertial sensors (e.g., accelerometers, gyroscopes, compasses, etc.) to measure an inertial state of the mobile device. Inertial measurements obtained from these inertial sensors may be used in combination with SPS signals to provide estimates of geographic position and heading.
However, conventional methods for combining inertial measurements and SPS signals have thus far been insufficient to effectively reduce error or location uncertainty. Accordingly, new techniques are needed for improving the speed and accuracy of position sensing.